HDI circuits are formed by mounting two or more semiconductor chips so that those surfaces having electrodes are coplanar, and then applying a layer of visually transparent, ultraviolet absorbent dielectric material, generally polyimide, over the electrode or bonding pad sides of the juxtaposed semiconductor chips. A laser is optically aligned to the position of each chip through the transparent dielectric, and an ultraviolet laser beam is used to make holes through the dielectric material at the locations of the electrodes of the semiconductor chips.
Improved HDI manufacturing is desired.